1. Field of the Invention
This invention relates to an ink jet recording apparatus which records on a recording medium by discharging ink on the recording medium.
2. Related Background Art
A recording apparatus such as a printer, copying machine and facsimile is so constructed that an image consisting of a dot pattern is recorded on a recording sheet such as paper and thin plastic sheet by driving an energy generating unit for a recording head in accordance with image information to be transmitted.
Among said recording apparatus, the ink jet recording apparatus has very low noise during recording and a high-density multidischarge port is easily provided, and therefore it is capable of recording at high speed. Since color reproduction of a color image is also easy, it has been drawing attention recently.
Among the rest, a method to discharge and project an ink droplet by utilizing heat energy is capable of providing the highest density among all recording methods because a flow path can be formed by using the thin film technique, and accordingly, this can be said to be suitable for high-speed recording.
In a facsimile apparatus, for example, which is generally used, it was so constructed that a roll-shaped wound recording sheet is continuously conveyed under an area, where the thermal head has been placed, by the specified conveyance means, and recording is started by receiving a signal.
In case said ink jet recording head has been adopted as a recording head which records on a recording sheet, when an ink droplet, for example, adheres to the discharge port surface of the ink jet recording head for some reason, it is likely to drip and adhere to the recording sheet which is being conveyed below the recording head.
Since the conveyance route for the recording sheet is complicated and long, a recovery operation such as treating a jammed sheet, setting a new recording sheet and a replacement operation can also be troublesome.
In the ink jet recording apparatus, on the other hand, there is a supply system (such as ink tank, pump and pipe), which feeds ink to the recording head, and a recovery system (such as wiping means and cap), which normalizes the state of discharge of the recording head, in addition to the recording head, and the parts for these units are naturally located near the recording sheet pass.
When the recording sheet pass becomes complicated for this reason and thereby sheet conveyance trouble occurs, trouble may occur with the surrounding recovery system. Also there is a technical problem that ink leakage from parts of which the ink supply system is composed is likely to dirty the recording sheet as it passes.